Adrenal masses are nowadays more and more diagnosed incidentally. In t
he vast majority of cases these ''incidentalomas'' are benign adrenoco
rtical adenomas which do not compel operative therapy. In about 12 % o
f patients an endocrine activity is detected. with increasing tumor si
ze the risk of malignancy increases. This article summarizes recommend
ations, only to allow patients with endocrine activity or an increased
risk of malignancy to be selected for surgery. A small uncertainty wi
ll always remain, but may be minimized by an individually tailored fol
low-up.